Influenza A infections: predictors of disease severity.

Influenza affects approximately 10% of the world's population annually. It is associated with high morbidity and mortality rates due to its propensity to progress to severe acute respiratory infection, leading to 10-40% of hospitalized patients needing intensive care. Characterizing the multifactorial predictors of poor prognosis is essential for developing strategies against this disease. This study aimed to identify predictors of disease severity in influenza A-infected (IFA-infected) patients and to propose a prognostic score. A retrospective cross-sectional study was conducted with 142 IFA-infected out- and inpatients treated at a tertiary hospital between 2010 and 2018. The viral subtypes, hemagglutinin mutations, viral load, IL-28B SNPs, and clinical risk factors were evaluated according to the patient's ICU admission. Multivariate analysis identified the following risk factors for disease severity: neuromuscular diseases (OR = 7.02; 95% CI = 1.18-41.75; p = 0.032), cardiovascular diseases (OR = 5.47; 95% CI = 1.96-15.27; p = 0.001), subtype (H1N1) pdm09 infection (OR = 2.29; 95% CI = 1.02-5.15; p = 0.046), and viral load (OR = 1.43; 95% CI = 1.09-1.88; p = 0.009). The prognosis score for ICU admission is based on these predictors of severity presented and ROC curve AUC = 0.812 (p < 0.0001). Our results identified viral and host predictors of disease severity in IFA-infected patients, yielding a prognostic score that had a high performance in predicting the IFA patients' ICU admission and better results than a viral load value alone. However, its implementation in health services needs to be validated in a broader population.

Community respiratory viruses and healthcare-associated infections: epidemiological and clinical aspects.

BACKGROUND: Healthcare-associated infections (HAIs) impact morbidity, mortality, and hospitalization costs. The contribution of viruses to the overall burden of HAIs is not well described. AIM: To evaluate the prevalence and clinical findings in patients with HAIs caused by respiratory viruses. METHODS: An observational, analytical, cross-sectional study was conducted to evaluate patients with a viral nosocomial respiratory infection, occurring between January 2013 and December 2019. Outcomes, comorbidities, cause of hospitalization, seasonality, and presence of bacterial co-infection were assessed. FINDINGS: In all, 161 cases of HAIs with community respiratory viruses (CRVs) were identified through six years; 76.4% of patients had a median age of 2.8 years (interquartile range: 0.28-15.4 years). The main comorbidities in immunosuppressed patients were haematologic neoplasia (46.5%), myelodysplastic syndrome (33.8%), and haematopoietic stem cell transplantation (18.3%). In non-immunosuppressed patients, the most prevalent comorbidities were prematurity (49.1%), respiratory tract diseases (21.0%), and congenital malformations (19.3%). The viruses detected were human rhinovirus (36.6%), respiratory syncytial virus (21.7%), and the parainfluenza group (18.6%). The fatality rate was low (4.6%), and a higher incidence of HAIs occurred in the CRV seasonality period in southern Brazil. CONCLUSION: CRV circulation in the hospital environment is frequent, and likely involves healthcare workers and visitors as well as patients. More guidance on preventive measures in healthcare settings is required. In addition, care teams should consider these aetiologic agents in the differential diagnosis of patients with nosocomial pneumonia, giving opportunities to limit antibiotic use.

Standardization of a high-performance RT-qPCR for viral load absolute quantification of influenza A.

Influenza is an acute viral infectious respiratory disease worldwide, presenting in different clinical forms, from influenza-like illness (ILI) to severe acute respiratory infection (SARI). Although real-time quantitative polymerase chain reaction (qPCR) is already an important tool for both diagnosis and treatment monitoring of several viral infections, the correlation between the clinical aspects and the viral load of influenza is still unclear. This lack of clarity is primarily due to the low accuracy and reproducibility of the methodologies developed to quantify the influenza virus. Thus, this study aimed to develop and standardize a universal absolute quantification for influenza A by reverse transcription-quantitative PCR (RT-qPCR), using a plasmid DNA. The assay showed efficiency (Eff%) 98.6, determination coefficient (R2) 0.998, linear range 10^1 to 10^10, limit of detection (LOD) 6.77, limit of quantification (LOQ) 20.52 copies/reaction. No inter and intra assay variability was shown, and neither was the matrix effect observed. Serial measurements of clinical samples collected at a 72h interval showed no change in viral load. By contrast, immunocompetent patients have a significantly lower viral load than immunosuppressed ones. Absolute quantification in clinical samples showed some predictors associated with increased viral load: (H1N1)pdm09 (0.045); women (p = 0.049) and asthmatics (p = 0.035). The high efficiency, precision, and previous performance in clinical samples suggest the assay can be used as an accurate universal viral load quantification of influenza A. Its applicability in predicting severity and response to antivirals needs to be evaluated.

Enterovirus D68-associated respiratory infection in southern Brazil, 2018 - A population-based laboratory surveillance.

Enterovirus D68 (EV-D68) strain was confirmed in 36/69-52.2% of enterovirus-positive samples collected through surveillance networks for severe acute respiratory infections (SARI) and influenza-like illness (ILI) in southern Brazil in 2018. This finding settles the sustained circulation of EV-D68 in southern Brazil.

Nosocomial infections with metallo-beta-lactamase-producing Pseudomonas aeruginosa: molecular epidemiology, risk factors, clinical features and outcomes.

BACKGROUND: Metallo-ß-lactamases (MBLs) have emerged as one of the most important bacterial resistance mechanisms because of their ability to hydrolyse virtually all ß-lactam agents. MBL-producing Pseudomonas aeruginosa (MBL-PA) are an important cause of nosocomial infections, particularly in intensive care units (ICUs), where they are associated with serious infections and present a significant clinical risk. AIM: To assess the molecular epidemiology, risk factors and outcomes of nosocomial infections caused by MBL-PA in a teaching hospital in Southern Brazil. METHODS: From January 2001 to December 2008, 142 carbapenem-resistant P. aeruginosa strains were isolated from distinct clinical samples from hospitalized patients. These isolates were screened for MBLs, and underwent polymerase chain reaction, sequencing and pulsed-field gel electrophoresis (PFGE). Patients infected with carbapenem-resistant MBL-PA were considered as cases, and patients infected with non-MBL-PA were considered as controls. FINDINGS: Eighty-four of 142 patients with positive carbapenem-resistant P. aeruginosa cultures met the criteria of the Centers for Disease Control and Prevention for infection. Fifty-eight patients were infected with MBL-PA (69%) and 26 patients were infected with non-MBL-PA (31%). Multi-variate analysis revealed that ICU stay [P = 0.003, odds ratio (OR) 4.01, 95% confidence interval (CI) 1.15-14.01] and urinary tract infection (P = 0.001, OR 9.67, 95% CI 1.72-54.48) were important risk factors for MBL-PA infection. Patients infected with MBL-PA showed faster onset of infection (P = 0.002) and faster progression to death (P = 0.04). CONCLUSIONS: These results showed the severity of MBL-PA infections, and demonstrated the urgent need for strategies to improve infection control measures to prevent an increase in these nosocomial infections.

Evaluation of the Alere Pima™ for CD4+ T lymphocytes counts in HIV-positive outpatients in Southern Brazil.

CD4 + lymphocyte counts are routinely ordered during the early phases of antiretroviral therapy and for prophylaxis of opportunistic infections in HIV-positive patients. Flow cytometry is the standard methodology for CD4 counts in Brazilian reference laboratories. However, these laboratories are located in large cities, frequently distant from patients, thus limiting patient access and delaying results. We compared a point-of-care test with flow cytometry determination of CD4(+) T lymphocyte counts in HIV patients. We analysed 107 consecutive samples by both methods. Overall, the point-of-care test performed well, with excellent agreement between it and the standard method. Test results were concordant for patients with CD4(+) T lymphocyte values above and below 200 cells/mm (3). The performance characteristics obtained were sensitivity 94% (95% CI 89.5-98.5%), specificity 93% (95% CI 88.2-97.8%), positive predictive value 86% (95% CI 79.4-92.6%), and negative predictive value 97% (95% CI 94-100%). The high sensitivity and specificity of the point-of-care test methodology suggest its utility as an alternative method for rapid measurement of CD4(+) T lymphocytes in patients with limited access to reference laboratories, enabling prompt therapeutic intervention for patients at risk of progression to AIDS.

Human metapneumovirus infection in hematopoietic stem cell transplant recipients.

UNLABELLED: Human metapneumovirus (hMPV) was described in 2001 and has been associated with both upper and lower respiratory tract infection (URTI and LRTI, respectively), especially in children, the elderly, and in immunocompromised patients. The objective of this study was to identify hMPV as the etiological agent of acute respiratory infection in hematopoietic stem cell transplant (HSCT) patients and to determine the clinical features of hMPV infection in these patients. METHODS: The study was performed retrospectively in 769 respiratory samples obtained from immunocompromised patients submitted to HSCT over a period of 6 years. RNA was extracted by the guanidinium thiocyanate method, and reverse transcription polymerase chain reaction assay was performed to amplify a 928pb fragment of the hMPV N gene. RESULTS: hMPV was present in 19 (2.5%) samples. The mean age of infected patients was 18.3+/-10.8 (range, 3-41). Sixty-six percent of hMPV infections occurred during autumn, winter, and spring months. Three episodes showed co-infection with more than 1 virus. Two patients (11.1%) were infected a few days into the conditioning period and 9 (50%) in the first 3 months after the transplant. The majority of patients (72.2%) presented URTI alone with flu-like symptoms (cough, fever, headache, wheezing), while 5 patients (27.8%) had LRTI (pneumonia). No patient died from complications associated with the hMPV infection. CONCLUSIONS: hMPV has been reported as a respiratory pathogen in HSCT patients. We suggest that hMPV infection should be routinely investigated in this population, mainly in children, to prevent nosocomial transmission during transplant proceedings and to avoid the risk of progressing to complications due to LRTI.

Impact of respiratory infections by influenza viruses A and B in pediatrics patients from Federal University of Paraná, Brazil.

The objective of the present study was to determine the impact of influenza virus on pediatric hospitalized patients. We retrospectively reviewed records of children with laboratory diagnoses, by cell culture and/or indirect immunofluorescence assay, of influenza virus seen in a period of 6 years. A total of 1,033 samples were analyzed, 45 (4.3%) of them being reactive to influenza virus. Thirty-one samples were positive to influenza A virus and 14 to influenza B. The frequency of hospitalization in intensive care and medical emergency was found to be high. Three (8.6%) patients died, two of them due to respiratory failure. Low frequency of influenza virus infection was observed in the study. The data suggest the need of more efficient epidemiological surveillance measures in order to obtain reliable information to better assess the impact of the virus on our region and determine the need of preventive measures, such as immunization.

Impact of respiratory infections by influenza viruses A and B in pediatrics patients from Federal University of Paraná, Brazil

The objective of the present study was to determine the impact of influenza virus on pediatric hospitalized patients. We retrospectively reviewed records of children with laboratory diagnoses, by cell culture and/or indirect immunofluorescence assay, of influenza virus seen in a period of 6 years. A total of 1,033 samples were analyzed, 45 (4.3 percent) of them being reactive to influenza virus. Thirty-one samples were positive to influenza A virus and 14 to influenza B. The frequency of hospitalization in intensive care and medical emergency was found to be high. Three (8.6 percent) patients died, two of them due to respiratory failure. Low frequency of influenza virus infection was observed in the study. The data suggest the need of more efficient epidemiological surveillance measures in order to obtain reliable information to better assess the impact of the virus on our region and determine the need of preventive measures, such as immunization.

Comparison of PCR, enzyme immunoassay and conventional culture for adenovirus detection in bone marrow transplant patients with hemorrhagic cystitis.

BACKGROUND: Adenovirus-associated hemorrhagic cystitis (HC) has become a recognized sequel of immunosuppression. The diagnosis of viral infection is usually determined by viral cultures. OBJECTIVES: Analysis of different diagnostic methods for adenovirus (AdV) detection in bone marrow transplant patients with hemorrhagic cystitis. STUDY DESIGN: We describe a prospective study for AdV detection in the urine of patients with hematuria in the first 100 days after bone marrow transplant (BMT), comparing different laboratory techniques, PCR, enzyme immunoassay (EIA) and conventional culture. RESULTS: A total of 143 urine samples were analyzed, 75 collected in the pre-transplant period with and without hematuria and 68 post-transplant, only with microscopic or macroscopic hematuria. After BMT, hematuria occurred in 38.9% of patients, being more frequent in unrelated donor transplants. AdV was isolated in one pre-transplant patient without symptoms and in three post-transplant patients with HC grades 3 and 4 (severe), who were in month 2 or 3 post-transplant. Compared to culture as the gold standard, the accuracy, specificity and sensitivity of EIA were 95, 30 and 100% and for PCR were 63, 100 and 60%, respectively. CONCLUSIONS: We concluded that despite technical difficulties and the long time that elapsed before results were obtained, cell culture still remains the best method for adenovirus detection in the urine of patients with hemorrhagic cystitis.

Padronizaçäo da técnica antigenemia para a detecçäo do citomegalovirus / Padronization of antigenemia metodology for detection of citomegalovirus

Antigenemia para citomegalovirus (CMV) é um importante marcador de evoluçäo de doença e eficácia de tratamento em pacientes imunocomprometidos. O objetivo desse estudo foi comparar diferentes técnicas de processamentos e de imunomarcaçäo para a detecçäo da proteína da matrix do CMV pp65 em leucócitos do sangue periférico. Amostras de sangue coletadas de pacientes submetidos ao transplante de medula óssea (TMO) foram processadas e imunomarcadas por diferentes metodologias. Separou-se leucócitos de sangue periférico, utilizando-se duas técnicas, sedimentaçäo espontânea a 37§C (Processamento 1) e a sedimentaçäo com Dextran (Processamento 2), após a lise eritrocitária procedeu-se a contagem dos leucócitos, ajuste da densidade celular e o preparo das lâminas que continham (2x10 a quinta potência) células, por citocentrifugaçäo. As lâminas, obtidas através das diferentes técnicas de processamentos, foram coradas, utilizando-se a metodologia de Imunoperoxidase (IP) e os resultados obtidos foram analisados de acordo com parâmetros qualitativos e quantitativos. Também avaliou-se duas diferentes técnicas de imunomarcaçäo: IFI Imunofluorescência Indireta) e IP onde comparou-se o número de células positivas. Obteve-se lâminas de melhor qualidade pelo processamento 1 e um maior número de célu;as positivas com técnica de IP